Conventionally, coating with a hard coating of TiN, TiCN, TiAlN, etc. has been performed for the purpose of enhancing the wear resistance of jig or tool using, as the substrate, a cemented carbide, a cermet, a high-speed tool steel, an alloy tool steel, etc. However, accompanying an increase in the hardness of a work material and a speedup of the cutting rate, realization of a hard coating having increased wear resistance is required.
As the hard coating having more excellent wear resistance than a hard coating of TiN, TiCN, TiAlN, etc., for example, Patent Document 1 has proposed a technique of satisfying a predetermined composition ratio in a hard coating represented by (Ma,Alb,[Cr1-αVα]c)(C1-dNd) (in which a, b and c represent the atomic ratios of M, Al and Cr+V, respectively, d represents the atomic ratio of N, and α represents the atomic ratio of V), assuming that M is at least one element selected from the group consisting of Ti, Nb, W, Ta, and Mo.
This technique could realize a hard coating more excellent in the wear resistance than a hard coating that has been conventionally used, such as TiN, TiCN and TiAlN, but it is demanded to further improve the wear resistance by maintaining the hardness in a high-temperature environment, i.e., enhancing the stability at a high temperature. In order to increase the wear resistance, the oxidation resistance during high-speed cutting must be enhanced as well. These properties are required also in an environment using a wet lubricant.